如何在异步函数中使用'yield'？

Question

我想使用生成器yield和异步函数。我阅读了this topic，并编写了下一段代码：

import asyncio

async def createGenerator():
    mylist = range(3)
    for i in mylist:
        await asyncio.sleep(1)
        yield i*i

async def start():
    mygenerator = await createGenerator()
    for i in mygenerator:
        print(i)

loop = asyncio.get_event_loop()

try:
    loop.run_until_complete(start())

except keyboardInterrupt:
    loop.stop()
    pass

但我错了：

SyntaxError:异步函数中的“yield”

如何在异步函数中使用yield生成器？

Answer 1

这应该适用于Python3.6（使用3.6.0b1测试）：

import asyncio

async def createGenerator():
    mylist = range(3)
    for i in mylist:
        await asyncio.sleep(1)
        yield i*i

async def start():
    async for i in createGenerator():
        print(i)

loop = asyncio.get_event_loop()

try:
    loop.run_until_complete(start())

except KeyboardInterrupt:
    loop.stop()
    pass